MG Duff 818298Q1 Mercury Outboard Bar Anode 194 mm

MG Duff CM818298 Mercury 818298Q1 Outboard Bar Anode 194 mm – Zinc / Aluminium

The MG Duff CM818298Z and CM818298A are sacrificial bar anodes designed for compatible Mercury outboard and MerCruiser marine propulsion applications. The aluminium version is listed with Mercury original part reference 818298Q1.

These anodes are identified for Mercury 40 HP and V6 135, 150 and 175 HP Verado applications. They provide sacrificial corrosion protection for electrically connected metallic components of the propulsion system.

Both variants measure 194 mm in length, 51 mm in width and 12 mm in height. Each has four fixing holes, with mounting centre measurements of 178 mm and 167 mm, and a specified 6 mm stud size.

The series is available in zinc and aluminium. The zinc version weighs 0.66 kg, while the aluminium version weighs 0.26 kg.

Technical Specifications

Available Variants

The two variants share the same stated body dimensions and mounting measurements. Their weights differ according to the sacrificial material.

Mercury and MerCruiser Compatibility

The MG Duff CM818298 series is listed for compatible Mercury and MerCruiser marine propulsion applications, including the following engine references:

• Mercury 40 HP
• Mercury V6 135 HP
• Mercury V6 150 HP
• Mercury V6 175 HP Verado

The supplied product information identifies Mercury part number 818298Q1 for the aluminium variant.

Engine power ratings alone do not confirm fitment with every model or production year. Verify the original anode reference, engine configuration and mounting dimensions before ordering.

Bar Anode Dimensions and Mounting

Both MG Duff CM818298 variants feature a bar-shaped sacrificial anode body with the following dimensions:

• Body length: 194 mm
• Width: 51 mm
• Height: 12 mm
• Number of fixing holes: 4
• Fixing-hole centre measurements: 178 mm and 167 mm
• Stud size: 6 mm

The two mounting centre measurements are provided in the product specifications. Their respective positions in the four-hole mounting pattern should be verified against the original anode or a technical drawing.

Zinc and Aluminium Sacrificial Protection

The MG Duff CM818298 series is available in two sacrificial materials:

• Zinc – CM818298Z: Weighs 0.66 kg and is commonly used in saltwater marine corrosion protection systems.
• Aluminium – CM818298A: Weighs 0.26 kg and is used in suitable saltwater and certain brackish-water corrosion protection systems.

When correctly installed with suitable electrical continuity to the metallic components requiring protection, the sacrificial anode material corrodes preferentially, helping reduce galvanic corrosion.

The material should be selected according to the operating water conditions and the propulsion equipment manufacturer's recommendations.

Inspection and Replacement

Inspect the sacrificial bar anode periodically during routine outboard or sterndrive maintenance. Replace it when the material becomes significantly depleted, damaged or no longer securely attached.

Before fitting a replacement, confirm the four-hole mounting configuration and inspect the electrical contact surfaces. Follow the applicable Mercury or MerCruiser installation instructions.

Part Numbers and References

• MG Duff Zinc: CM818298Z
• MG Duff Aluminium: CM818298A
• Mercury Reference: 818298Q1 (listed with the aluminium variant)
• Zinc Weight: 0.66 kg
• Aluminium Weight: 0.26 kg

Scope of Supply

1 × MG Duff Mercury / MerCruiser Outboard Bar Anode in the selected material:

• CM818298Z – Zinc; or
• CM818298A – Aluminium.